Method for fastening workpieces to metal plates



March 30, 1954 G. K. J. BROBERG 2,673,390 METHOD FOR FASTENINGWORKPIECES TO METAL PLATES Filed Aug. 17, 1949 2 Sheets-Sheet 1g'wyf/fjhzfimaj WW 4 BY W March 30, 1954 METHOD FOR FASTENING WORKPIECESTO METAL PLATES Filed Aug. 17, 1949 G. K. J. BROBERG 2 Sheets-S heat 2 25 T 1 V" K ,Z"

- INVENTOR/ w zw Mala ATTORNEY Patented Mar. 30, 1954 METHOD FORFASTENING WORKPIECES TO METAL PLATES Georg Karl Johan Broberg, Solna,Sweden, as-

signor to AB Svenska holm, Sweden Flaktfabriken, Stock- ApplicationAugust 17, i949, Serial N 0. 110,858

Claims priority, application Sweden August 28, 1948 3 Claims. 1

This invention relates to a method for fastening an edge of a work-pieceto the surface of a sheet metal plate or the like.

The object of the invention is to provide a simplified and cheap way offastening an edge of a work piece to the surface of a sheet metal plate.According to hitherto known methods, welding or soldering has beenutilized for such fastening operations, which has meant a complicationof the manufacture, or the use of such complicated mechanical machiningmethods and fastening means that they have made the production moreexpensive.

The method according to the invention is, in the first place,characterized in that an edge of the work-piece is placed underneath andin contact with the underside of the metal plate to serve as a die,while a punch is forced through said metal plate from the upper surfacethereof to simultaneously out two spaced slots correspondingsubstantially to the Width and contour of the underlying edge of saidwork-piece and to displace or depress the metal plate adjacent saidslots, after which another punch deforms the material of the metal platelocated between said slots and also deforms or upsets the underlyingedge of the work-piece which serves as the die, so that said deformed orupset edge of the workpiece is interlocked between the displaced ordepressed portions of said plate and the deformed material between saidslots.

Other characteristic features of the method according to the inventionare treated in connection with two embodiments thereof more specificallydescribed in the following specification.

The invention is bodiments in the accompanying drawings wherein, forpurposes of illustration, Figures 1-4 show different phases of theproduction of one embodiment and Figures -11 show diiferent phases ofthe production in accordance with the other embodiment.

According to the invention metal plate l2 serves illustrated in two ofits emas a die for the punch pressed down against the metal plate [3.

In Figure 2, the shape of the metal plate 13 is shown after the punch Mhas accomplished its the form of the punch.

Figure 4. shows a horizontal View of Figure 2 after the punch M has beentaken away. From Figures 2 and 4 it is evident that the punch M, asindicated by the lines l5 and IS in Figure 4, cuts a metal strip it outof the metal plate I3, which metal strip is united at both ends withmetal plate I3. Simultaneously with the cutting action just referred to,the punch l4 displaces or depresses from the metal plate l3, tWo tonguesI9 and 2B. These tongues form an angle with each other as will beapparent from Figure 2. From the same figure it is further apparent thatthe free edges of tongues I9, 23 lie closely adjacent the work-piece l2at opposite sides thereof. The free edges of the tongues I9, 20 do notmake close contact with the opposite sides of work-piece !2, as thereis, in reality, a little space between the free edges of these tonguesand the sides of said work-piece, as best shown in Figure 2a.

Complete contact between said free edges and the sides of saidwork-piece may be obtained, however, by supportin the tongues I9, 20during a the tongues, by deforming, are pressed into contact with themetal plate I2 as shown in Figure 2, This contact may, on the otherhand, be obtained in connection with a second punching operation inwhich the punch l4 further bends down the tongues I9, 20 so that thedown pressed tongues in Figure 4 form grips resembling thumb grips, thesides 2|, 22 and 23, 24 of which are united with metal plate 13. Thereference numerals 2|, 22, 23, 24 may, however, also represent lines(Figure 4) along which the metal plate l2 has been cut by the punch l4.From Figure 2 it is evident that after this punching, a cavity 25 hasbeen formed between the metal strip l8 and the upper surfaces of thetongues l9 and 20.

In Figure 3, showing a cross section of a fastening joint completeaccording to the embodiment deformed the metal strip l8 and the upperedge of metal plate l2. This second punch is not shown in the drawing.By supporting the tongues I9, 20 during this second punching operationby means of a support, the free edges of these tongues may, as has beenmentioned above, during the M, when said punch is same punchingoperation, be brought into complete contact with metal plate l2. Afterthis second punching operation, the, metal strip I8 is flattened asindicated by reference character lBa (Figure 3), and lies against andpresses against the punched out edge 26 of metal plate i2, so. that edge26 is held firmly and steadily between metal strip iBa and tongues l9,2i).v Thisfastening method is simple, cheap and effective andis.possible to accomplish with simple means and with rapidity.

Figures 5, 6 and "I show a side view, a cross section and a horizontalview, respectively, of the original position of parts for the fasteningof an edge of one or more U-shaped metal plates. 21. to the surface of aplane metal plate 28, which,,for, instance, consists of a part of aclosed frame work. Figures 8 and 9 correspond toFigures 5 and 6 and showthe appearance of metal plates 21, and 28 after accomplishing thefirstpunching operation on metalplate-28, with punch 29, each U-sha-pe-dmetal plate 2? serving as a die during this initial punching operation.Punch 29 has thesame width and form asthe inner edge of the U-shapedmetal plate 21. The form of punch 29, therefore, varies in accordancewith the form of the work-piecewhich is to be fastened to the plate 28,In the example shown, the punch 29 has a cross-sectional form orconfiguration corresponding to the surface 30, 3|, 32, 33 in Fig. 7. Thelo wer surface of punch 29 is arched according to Figure 9, and the sidesurfaces 35 and 35 of punch 29 form sharp edges (see Figure 8) withbottom surface 35- in order to out metal plate 23, While the other sidesurfaces 31 and 38 of the punch 29 form rounded edges with the bottomsurface 36 of;the punch in order not to cut metal plate 23 (See; Figure9). By the pressing down of the punch-29 against metal plate 28, a metalstrip 39 is cut and is pressed down out-of metal plate 28, which metalstrip with its downwardly bent part liesagainst the inner sides of thelegs of metal plate 2?, each end of said downwardly bent part beingunited with metal plate 28. In Figure '7, line (ML-3| and 32-33represent cutting lines where metal plate 28 is cutthrough bypunch 29,while metal strip 39 is united with metal plate 28 along the places3l--32 and wig-33. Each U- shaped metal plate 2! is, after this punchingoperation, partly held by metal plate 28. For,com plete fastening of theU-shaped metal plates to metal plate 28, still one or more punchingoperations performed with another punch, are required. These operationsare evident from Figures 10 and ll, in which Figure 10 corresponds toFigure 8 after accomplishing these last punching operations, and Figure11 is a cross-section of Figure 10 between two U-shaped metal plates 21lying near each other,

If a plurality of U-shaped metal plates v2", arranged in a line aftereach other and at a distance fromeach other, are to be fastened to acommon metal plate 28, this is effected by means of a punch with a form36 shown in full lines in Figure 10, which punch is shown in sideelevation in Figure 11. Thispunch 40 having an arched bottom surface, ispunched downwardly against the remaining parts, designated 4! in Figure8, of the metal plate 28, said parts being situated between the downpressed metal strips 39. By this down pressing, the parts M are bent tothe form designated a l a in Figures 10 and 11, while simultaneouslywith such bending, the upperedgesof the u shaped metal plate. are e e md so they are bent in over the metal strips 39. The

that,

last mentioned bendings are designated 42 in Figure 0. Parts Ma and 42are bent only, or else they are both bent and stretched, depending uponthe force with which the deformation is effected. By the method heredescribed, the punch it at each operation thereof fastens to metal plate28 one edge of each of two U-shaped metal plates2'l' lying, near eachother, and as the punch 48 passes over all U-shaped metal plates, all ofthese are fastened at both sides. Punch M) is also utilizable forfastening the outermost legs of the outermost u-shaped metal plates, butin Figure 0 this is not shown. Instead, this figure indicateshow theseoutermost legs may be fastened, if desired, by means of a punch with asomewhat differings'hape (compare the impression 4H) of this punch inFigure 10) It is evident from what isdescribed that with this fasteningmethod, the ends 62 of the U-shapedmetal plates are brought to a secureand locking engagement between parts Ma and 39 of metal'plate 2B in asimple and cheap manner.

If the object is only to fasten one U'-shaped metal platen to a metalplate 28, this may be eifected. by means. of a second punchsimultaneously effecting the deformations Ma and 42 at both sides of oneU-shapedmetal plate 21. A punch or deforming tool of this type isindicated in Figure 10, which punch includes a first punch member it anda second punch member Ma indicated in dash-dotted lines in said figure.

The invention here described is not restricted to the embodiments shownwhich are only to be consideredas examples because the idea oftheinvention may be realized also in other ways.

Having now descrbedmy invention, what I claim as new, and desire tosecure by United States Letters Patent, is:

1. In the method of fastening a work-piece having spaced wall portionsat one end edge thereof to a plane plate member disposed-perpendicularto the wall portions of the workpiece, the step which comprise utilizingthe work-piece as a die and'severing and displacing from the plate inthe direction of the work-piece an integral strip portion to engageendwise inwardly of the work-piece between the spaced wall portionsthereof, and deforming simultaneously the portions, of'the platelaterally adjacent said strip and the underlying end'edge portions ofthe spaced walls of the work-piece to interlock said endedgeportions ofthe work-piece between the displaced strip and deformed portions of theplate.

2. Inv the method of fastening a work-piece having spaced wall portionsat one end edge thereof to a plane plate member disposed perpendicularto the wall portions of the workpiecathe steps which comprise ut'lizingthe 'work-pieceas a die, severing from the plate an integralstrip'portion and simultaneously displacing the'samein the directionofthe work-piece to engage endwise inwardlythereof between the spaced wallportions thereof, andthen deformingin the'directi'on of the work-piecethe plate portions at opposite sides of the displaced stripto cause theunderlying end edges of the spaced walls of the workpiece'to ,be turnedinwardly thereofand engaged over theintermediate displaced stripportionof the plate so that the work-piece end is interlocked betweenthe displaced. strip and deformed, edge portions of the plate.

3. The methodof. fastening a workqpiece at an edge thereof to. aplaneplate ..member. disposed substantially perpendicular to said work-piece,

which comprise the steps of placing an edge 01' the work-piece intocontact with a surface of the plate member with the plate memberextending beyond at least one end of said edge, utilizing said edge as asupporting die, severing from the plate member an integral stripcorresponding substantially to the width and contour of said edge byforming spaced cuts in the plate member adjacent opposite sides of saidedge and within the area of said plate member and displacingsimultaneously with said severing and in the direction of saidwork-piece integral tongue portions disposed at opposite sides of saidwork-piece, deforming simultaneously the said integral strip andupsetting said edge, and deforming said tongue portions toward saidworkpiece to bring the free edges thereof into contacting relation withopposite sides of said work-piece inwardly thereof from said edge andbeneath said upset edge, whereby to interlock said upset edge betweensaid deformed integral strip and said tongue portions of said platemember.

GEORG KARL J OHAN BROBERG.

Number Number Name Date Schoen Jan. 30, 1894 Stimpson Nov. 16, 1909Furguson Nov. 29, 1910 Wenn June 8, 1926 Williams Sept. 2, 1941 EckelSept. 16, 1947 FOREIGN PATENTS Country Date Germany Oct. 15, 1930

